I enjoy seeing all the four-leaf clovers people have found and posted to iNaturalist! If you want to help search for observations to add to this project, many should show up under these filters (unless they've all already been added to the project by someone else recently):

Searching descriptions
https://www.inaturalist.org/observations?not_in_project=four-leaf-clovers-of-inaturalist&subview=grid&taxon_ids=51876&q=four-leaf
https://www.inaturalist.org/observations?not_in_project=four-leaf-clovers-of-inaturalist&subview=grid&taxon_ids=51876&q=four-leaved
https://www.inaturalist.org/observations?not_in_project=four-leaf-clovers-of-inaturalist&subview=grid&taxon_ids=51876&q=4-leaf
https://www.inaturalist.org/observations?not_in_project=four-leaf-clovers-of-inaturalist&subview=grid&taxon_ids=51876&q=4-leaved
(and other variants, perhaps add higher numbers?)

Searching comments
https://www.inaturalist.org/comments?commit=Search&q=four-leaf
(and variants used above)

They may also be found by broadly identifying clover observations, or targetted searches for observations around patches that are known to contain four-leaved individuals.

Make sure that there is actually a four-leaf clover in the observation! Sometimes people will mention that it's possible but that they didn't actually find one.